Background Surgical stress causes a helper T-cell type 2 (Th2)-dominant status and disturbs the Th1/Th2 cytokine balance. Anesthesia can suppress the stress response to surgery, therefore it may inhibit the imbalance in the Th1/Th2 ratio. In this study, we assessed if propofol anesthesia and sevoflurane anesthesia influence the Th1/Th2 cytokine balance, and which anesthesia method better attenuates this ratio.Methods Twenty-eight patients with an American Society of Anesthesiologists (ASA) physical status of I undergoing laparoscopic cholecystectomy were selected. They were randomly allocated into two groups of 14. Group 1 received propofol anesthesia by a target-controlled-infusion (TCI) pump and group 2 received sevoflurane anesthesia.Non-invasive blood pressure, heart rate, and end-expiration CO2 partial pressure were monitored during anesthesia. The depth of anesthesia was measured using the bispectral index (BIS), and maintained between 50 and 60. During surgery we adjusted the doses of propofol and sevoflurane according to the BIS. Samples of peripheral blood were taken before the induction of anesthesia (T1), after the induction of anesthesia (T2), at the beginning of surgery (T3), at the end of surgery (T4) and on the first day after surgery (D1). Blood samples were analyzed to give the Th1/Th2 ratio and plasma level of cortisol.Results Non-invasive blood pressure, heart rate and end-expiration CO2 partial pressure were not notably different in the two groups. At T4, the percentage of T1 cells was higher in group 1 and had statistical significance (P ＜0.05). The percentage of T2 cells was not significantly different in the two groups. At T4, the difference in the Th1/Th2 ratio was significantly different. At T3, T4, and D1, the plasma level of cortisol was lower in group 1(P ＜0.05).Conclusion Compared with sevoflurane, propofol can preferably promote Th cells to differentiate into Th1 cells and inhibit surgical stress. Propofol may therefore be immunoprotective for such patients.